Multi-core conductive wire and a method of manufacturing the same

ABSTRACT

An object of the invention is to provide a multi-core conductive wire having the small number of manufacturing processes and a terminal with high strength, and a method of manufacturing the multi-core conductive wire. 
     The multi-core conductive wire is provided with a terminal, at the end portion thereof, where individual strands of the multi-core conductive wire are entangled with each other and the terminal is molded by subjecting to pressure-molding. 
     A method of manufacturing a multi-core conductive wire comprises a step of processing the multi-core conductive wire into a state where individual strands of the multi-core conductive wire are partially entangled with each other; a step of temporarily molding the processed portion; and a step of further applying pressure to the temporarily molded portion for pressure-molding or plastic working.

TECHNICAL FIELD

The present invention relates to a novel multi-core conductive wire tobe used for various sorts of electric equipment, and more particularlyto a multi-core conductive wire having a novel terminal and itsmanufacturing method.

BACKGROUND ART

In the prior art, various methods have been used as a processing methodof a terminal portion of a multi-core conductive wire (called conductivewire and multi-core wire) to be used in electric equipment. As called amulti-core conductive wire, since a large number of wires are used inthe conductive wire, a simple method of processing a terminal portion insuch a multi-core conductive wire has not been yet established, being indifficulties.

On the other hand, in the processing of the terminal portion of themulti-core conductive wire, also such technology is demanded that othermaterial wrapping the multi-core conductive wire is not used but theprocessing can be performed by only the multi-core conductive wire.

As a method of processing a terminal portion in the prior art, when arelatively small number of multi-core conductive wires are used, theconductive wires are fixedly secured to each other using a resistancewelder. When a large number of multi-core conductive wires are used, thefixing by the resistance welder is restricted. Therefore as a fixingmethod in the present state, plating is applied to the individualmulti-core conductive wires and the terminal portion is fixedly securedby the resistance welder utilizing the plating.

Respective methods have some merits and demerits. For example, with theformer, if the wires are welded with each other, the wires are heated upto the processing temperature which may attain to the melting pointthereof. Therefore the thermal damage of the wires themselves becomesgreat, resulting in increase of the resistance being fatal as theelectric equipment. Also with the latter, since the plating is appliedto the individual wires, the price of the wires themselves becomesexpensive. Further flexibility required as other factor is deteriorateddue to the plating film and the fixing by the resistance welding.

As above described, any method of processing a terminal portion in theprior art has some disadvantages. As a result, it is difficult toprocess a terminal portion of a multi-core conductive wire with highquality.

In order to connect a terminal portion to other connection terminal,such a method is generally performed that a conductive wire is insertedin a connecting conductor terminal, and the terminal having lateralspread and the conductive wire are joined with each other by means ofsoft soldering or caulking. That is, a conductive wire peeled off aninsulation tube is inserted into a connecting conductor terminal and issoldered by means of soft soldering. Otherwise, a conductor wire peeledoff an insulation tube is inserted into a connecting conductor terminaland is pressure-contacted for connection by a caulking machine. Theabove-mentioned connection in the processing of the terminal portion ofthe multi-core conductive wire is performed by other material forwrapping the multi-core conductive wire.

Japanese Patent Laid-open No. Hei 1-292775 discloses a method that anend portion of a multi-core conductive wire is previously inserted in ametal cylinder, and the metal cylinder is processed and molded into aterminal. Also Japanese Patent Laid-open No. Sho 55-113279 disclosesthat an end portion of a multi-core conductive wire is bundled by awire, and then is subjected to pressuremolding into a flat end portionand is brazed with other conductor by resistance heating.

In rotary machines such as a motor or an AC generator, or electricequipment for electric facilities of an automobile, for a breaker or thelike, in order to exhibit functions respectively, multi-core conductivewires are used widely as conductive wires. Processing of a terminalportion plays a very important role. Two methods are used in processingof a terminal portion. One is the case that a terminal portion of aconductive wire is connected to other connection terminal as abovedescribed, and the other is the case that a terminal portion of aconductive wire is fixedly secured and is treated as a single article.Even in a single article of the latter, it may sometimes be coupled withother conductor terminal. The multi-core conductive wires are used invarious sorts of electric equipment. Attendant on this, various sorts ofconductor wires are applied. That is, there are conductive wires beingdifferent from each other in the diameter of wire, the number of wiresor the like. Therefore it is desirable that processing of terminalportions of these conductive wires be easily performed.

When the number of the conductive wires in the terminal portion is inthe range of three to a large number (for example, 10,000), and moreovera range of the wire diameter is, for example, from 0.10 mm to 1.5 mm,approximately, it is very difficult that all different conductive wiresare fixedly secured together in the method of the prior art. Thus suchstructure for a terminal portion with high reliability has been desiredstrongly that terminal portions of many conductive wires having wirediameters ranging from smaller one to larger one can be fixedly securedwithout raising the heating temperature in the terminal portions ifpossible and without applying the plating or the like to the wires ifpossible.

The methods disclosed in Japanese Patent Laid-open No. Hei 1-292775 andJapanese Patent Laid-open No. Sho 55-11327 have problems in that thecoupling force between the wires is weak and further the number of themanufacturing processes is much.

An object of the present invention is to provide a multi-core conductivewire having the small number of manufacturing processes, a terminal withhigh strength, and a method of manufacturing the multi-core conductivewire.

DISCLOSURE OF INVENTION

The present invention provides a multi-core conductive wire wherein insuch irregular and uneven state that a molded end portion of amulti-core conductive wire or individual strands of the multi-coreconductive wire are partially entangled with each other in disorder, themulti-core conductive wire is subjected to compression-molding,pressure-molding or plastic working.

The present invention provides a multi-core conductive wire wherein insuch irregular and uneven state that a molded end portion of amulti-core conductive wire or individual strands of the multi-coreconductive wire are partially entangled with each other in disorder, themulti-core conductive wire is subjected to processing or molding insimilar manner to that as above described, and a hole or the like toenable connection to other connection terminal is processed.

The present invention provides a multi-core conductive wire wherein insuch irregular and uneven state that a molded end portion of themulti-core conductive wire is entangled or the multi-core conductivewire is entangled with a molding assisting material in disorder, themulti-core conductive wire is subjected to processing or molding, and ahole or the like to enable connection to other terminal is processed.

As a molding assisting material as above described, preferably amaterial is selected from the group of consisting of copper, tin, lead,silver and indium and molded in linear shape, powder state, band shape,plating, thermal spraying or the like.

For a multi-core conductive wire which has a wire diameter ranging from0.01 mm to 1.5 mm and the number of wire not less than 30 preferably notless than 100, the wire material of Cu, Al, Ag, Au or the like, may beused.

In the molded terminal structure of the present invention, it ispreferable that the conductor wires being different in the wire diameterbe combined, and that different wire materials be combined.

The present invention is characterized in that the multi-core conductivewire with the terminal portion subjected to molding as above describedis connected to other conductor terminal.

The present invention provides a method of manufacturing a multi-coreconductive wire, comprising: a processing step of molding an end portionof the multi-core conductive wire into irregular and uneven state wherethe end portion of the multi-core conductive wire or individual strandsof the multi-core conductive wire are partially entangled with eachother; a processing step of temporarily molding said molded end portion;and a step of applying compression- or plastic-working to said processedend portion and processing it into the molded article.

In the present invention, in order that the multi-core conductive wirehas the electric performance, in view of the necessity for the terminalportion to be integrated at first, it is preferable that molding todesired shape be performed in cold processing without thermal damage,and that the terminal portion molded in cold processing be connectedsubstantially to other electric conductor terminal.

The terminal portion molding can be achieved in that one end of themulti-core conductive wire is untied and the strands are entangled witheach other in disorder, in irregular and uneven state for molding. Thethus molded terminal portion can be sufficiently connected to otherconductor terminal. The molded article can be provided with a hole orthe like during the molding, and can be screwed utilizing the hole andalso can be joined using a general brazing.

That is, the multi-core conductive wire of the present invention isconstituted by stranded wire of copper. In this case, the multi-coreconductive wire is constituted by six bundles of the stranded wires. Theend portion is molded in such irregular and uneven state that themulti-core conductive wires are entangled with each other, and isintegrally molded.

In some case, the end portion is connected to other conductor terminal.As an example of the joining method, resistance brazing using aresistance welder is preferable. The resistance welder is used here.Because the heating and the pressure applying can be performedsimultaneously, and the joining can be performed in a short time. Sincethe joining is performed in the atmosphere in almost case, the shorterthe joining time, the less the reaction with oxygen. Thus the good jointcan be obtained. In order to make the junction more reliable, it ispreferable that the resistance welder adopt the heating and pressureapplying system in two stages.

In the case of the multi-core conductive wire, in the heating and thepressure applying at the first stage, the solder material with highresistance value is heated, and at the same time of the heating of thesolder material, also the multi-core conductive wire is heated tocertain temperature, and in the heating and pressure applying at thesecond stage, the material is melted and wets the wires of themulti-core conductive wire. Even if the solder material before the wiresof the multi-core conductive wire are heated at a time, it is not liableto wet. Consequently the heating in the two stages is more preferable.The heating and pressure applying system in the two stages is a systemto be used in the case where the multi-core conductive wires arerelatively much. When the multi-core conductive wires are relatively alittle, the heating and pressure applying system in one stage canperform the joining well.

As a solder material to be used in the present invention, a soldermaterial containing phosphorous is preferable. As a solder materialcontaining phosphorous, a solder material constituted by Cu alloycontaining P 3 to 8%, further Ag 4 to 7% or 13 to 17% by weight, ispreferable. Further such solder material may contain Sn and Au of 5% orless. In the solder material, during the joining, phosphorous removesoxide from the material to be joined and the wettability of the solderis improved and flux becomes unnecessary although it is usually requiredin the solder material. Thus the washing after the joining need not beperformed, and the corrosion of the material to be joined due to theremaining of the flux used conventionally can be eliminated. Since thesolder material containing phosphorous is preferably used in theresistance brazing, the solder foil is preferably arranged in thejoining interface. Its thickness and width are determined by size of themolding structure.

When a hole is provided on the end portion of the multi-core conductivewire, the end portion can be connected mechanically to other conductor.The hole is produced by processing at the same time during the coldmolding.

As a multi-core conductive wire material to perform the molding in thepresent invention, bare copper wire is used at almost case. In orderthat the compression force during the molding is decreased and thefixing force of the molded portion is made stronger, use of the moldingassisting material is effective. Although various substance may beconsidered as the joining assisting material, selection of materialsofter than the multi-core conductive wire itself is preferable. Becausewhen the molding is performed using the die, the soft material iselongated by the pressure application and is entangled with the wires ofthe multi-core conductive wire and has effect of improving theadhesibility of the multi-core conductive wire. As the material, softcopper, tin, lead, silver, indium or the like is recommended. The formin linear shape, powder state, band shape, plating, thermal spraying orthe like is recommended.

In the state of molding the multi-core conductive wire, straight wire,stranded wire, net wire and the like are applied, and the size and thewire diameter of the multi-core conductive wire are varied in responseto the conduction current in the electric performance.

Condition required in the multi-core conductive wire is the processingof the terminal portion of the multi-core conductive wire, in otherwords, that the conductive wires are electrically conducted with eachother without fail, and that malfunction is not produced for use in along period of time. In order to satisfy such condition, individualstrands of the multi-core conductive wire are entangled with each otherand the adhesibility between the strands is molded well.

As above described, the molded terminal structure portion of themulti-core conductive wire by the cold pressure-molding is molded insuch irregular and uneven state that the strands are entangled with eachother in disorder. Thus high fixing force and high binding force areexhibited between the individual strands and the molded terminalstructure portion has high strength.

Also when the compressed terminal molded article is connected to otherconductor terminal, for example, in the connection by brazing, thesolder material wets both terminals and thereby good joining can beachieved. Also in the connection by screw or rivet system, electricallystable characteristics can be obtained.

In the molded terminal structure portion manufactured in such a manner,it is proved that the fixing force of the molded terminal structureportion itself is high. Also in the connection to other terminalportion, the satisfactory state can be obtained. That is, the moldedterminal structure portion with little thermal damage can be obtained,and the multi-core conductive wire with high reliability can beconfirmed.

In the multi-core conductive wire, various materials, such as electriccopper wire, or silver wire, gold wire or respective wire materialssubjected to, for example, tin plating called in JIS, can be applied asmulti-core conductive wire of the present invention. As the terminalportion, also in shape such as square wire or elliptical wire, themanufacturing can be performed by the cold pressure-molding structure ofthe present invention.

In the multi-core conductive wires applied in the present invention,since bare wires are much used, the measure taking anticorrosiveproperty and acid resisting property into consideration is effective.For example, it is confirmed that covering a lead wire and a terminalportion with an insulator contributes to improvement of reliability.

In rotary machines such as a motor or an AC generator, or electricequipment for electric facilities of an automobile, for a breaker andthe like, in order to exhibit respective functions, multi-coreconductive wires are used much and the present invention is used forthese applications.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a multi-core conductive wire of theinvention cut in a prescribed length;

FIG. 2 is a constitution diagram of an apparatus for molding an endportion of a multi-core conductive wire of the invention in entangledstate;

FIG. 3 is a perspective view of a terminal portion of a multi-coreconductive wire where one end is untied and entangled in irregular anduneven state in disorder;

FIG. 4 is a perspective view of an apparatus performing temporarymolding of the end portion;

FIG. 5 is a perspective view showing a temporary molding state of theend portion;

FIG. 6 is a constitution diagram of a press performing pressure-moldingof the end portion;

FIG. 7 is a perspective view of a multi-core conductive wire having theend portion manufactured by pressure-molding of the invention;

FIG. 8 is a photograph by a microscope showing section of a moldingportion molded in the first embodiment of the invention;

FIGS. 9A and 9B are perspective views showing a structure where aterminal portion of a multi-core conductive wire is joined with otherconductor terminal by solder material, and a structure where a terminalportion of a multi-core conductive wire is connected to other conductorterminal by rivet;

FIG. 10 is a perspective view showing a molding structure with a holeformed by forming condition of the fourth embodiment of the invention;

FIGS. 11A and 11B are perspective views showing a structure where aterminal portion of a multi-core conductive wire is screwed to otherconductor terminal using a hole, and a structure where a terminalportion of a multi-core conductive wire is riveted to other conductorterminal using a hole;

FIGS. 12A and 12B show structures molded by forming condition of thefifth embodiment of the invention, where FIG. 12A is a perspective viewshowing a state where a square type terminal portion of a multi-coreconductive wire is connected to other conductor terminal, and FIG. 12Bis a perspective view showing a state where a round type terminalportion of a multi-core conductive wire is connected to other conductorterminal;

FIG. 13 is a perspective view of a multi-core conductive wire shown inthe sixth embodiment of the invention;

FIG. 14 is a sectional view of a joining apparatus joining a copperconductor with a multi-core conductive wire of the invention; and

FIG. 15 is a perspective view of a multi-core conductive wire obtainedin the sixth embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1

A multi-core conductive wire is constituted in that a bundle ofCu-stranded wire is formed by 2,413 wires each having a diameter of 0.05mm, and six bundles of stranded wires constituted by 14,478 wires arearranged in three rows and two stages in an arbitrary length (70 mm inthis case) and then are molded by cold compression.

The basic manufacturing processes of cold pressure-molding of thepresent invention will be described as follows. At first, as shown inFIG. 1, multiconductor stranded wires 1 are cut in a prescribed lengthand overlaid in two stages to form six bundles. As shown in FIG. 2, oneend of the six bundles is drawn by a prescribed length to be fixed by aholding jig 31. While a circumferential rotary brush 32 is rotated inthe circumferential direction, the end portion of the multi-corestranded wires 1 is rotated by an axial rotary brush 33 rotating aboutthe axis. As a result, as shown in FIG. 3, the multi-core stranded wires1 are twisted, and while the multi-core stranded wires 1 are rotated bythe brush, a lump state 3 is produced where strands are entangled indisorder irregularly and unevenly. Before the lump state 3 is producedby the rotary brush, the multi-core stranded wires 1 are held at aprescribed length, and the end portion 2 of the multi-core strandedwires 1 is once disentangled and extended from the center to theoutside.

Next, as shown in FIG. 4, pressure is applied by a die 34 using a punch35 and thereby a temporary molding portion 4 is provided, and as shownin FIG. 5, a shape larger than the size of the six bundles of thestranded wires is produced. The temporary molded portion 4 is arrangedin a press shown in FIG. 6, the end portion is fixed by the holding jig31 and a pressure of two to four tons is applied thereto by the punch 35to form a terminal 5 of a prescribed shape as shown in FIG. 7. Theterminal 5 has a shape of 8.2 mm×8.1 mm and about 4.5 mm in thickness.

Thus the end portion of one or plural bundles of multi-core conductivewires can be molded in a prescribed shape and integrated by coldprocessing. As above described, with the integrated terminal 5, thestranded wires 1 are entangled with each other irregularly and unevenly.FIG. 8 shows the section of the entangled stranded wires observed in amagnification of×20. In FIG. 8, the upper side shows the outside of theterminal 5 and the lower side shows the inside of the terminal 5. Asshown in FIG. 8, in the surface of the terminal 5, the stranded wires ofthe multi-core conductive wires are entangled with each otherirregularly in various directions by the rotary brush and are subjectedto work deformation. Then, the stranded wires are subjected todeformation along the pushing surface of the punch and molded in thelaterally laid state to the punch surface. The depth in the laterallylaid state of the individual wires is about 0.5 to 1 mm. The depth inthe laterally laid state of the individual wires in such manner isproportional to a degree of applied pressure. In this embodiment, theapplied pressure of 0.2 mm or more is preferable.

Embodiment 2

A multi-core conductive wire is constituted in that Cu straight wiresformed by 4,040 wires each having a diameter of 0.1 mm are arranged inan arbitrary length (70 mm in this case) and then are molded by coldcompression.

The manufacturing processes of cold pressure-molding of this embodimentare performed similarly to those of the first embodiment. At first, asshown in FIG. 1, multi-core straight wires 1 are cut in a prescribedlength. As shown in FIGS. 2 and 3, one end of the wire materials isfixed at a prescribed length, and the end portion 2 of the multi-corestraight wires is extended from the center to the outside. Next, the endportion 2 is rotated and twisted by a brush. While the multi-corestraight wires are rotated by the brush, a lump state 3 is producedwhere strands are entangled with each other in disorder irregularly andunevenly. Next, as shown in FIG. 4, a temporary molded portion 4 isprovided by a die, and as shown in FIG. 5, a shape larger than the sizeof the four bundles of the straight wires is produced. Pressure isapplied to the temporary molded portion 4 by a press shown in FIG. 6 toform a terminal 5 of a prescribed shape as shown in FIG. 7. The moldedarticle has a shape of 6.2 mm×6.1 mm and 3.5 mm in thickness. In thistime, the pressure of the press is about 3.2 tons.

Thus the end portion of the multi-core straight wires can be molded in aprescribed shape and integrated by cold processing. In the integratedmolded portion, the strands are entangled with each other irregularlyand unevenly as shown in FIG. 8.

Embodiment 3

FIG. 9 shows an example where a molded end portion of six bundles ofmulti-core conductive wires manufactured under the condition of thefirst embodiment is connected to another terminal plate 7. FIG. 9A showsan example of connection by brazing. A conductor terminal is a Cu-platewith a thickness of 4 mm to which Ag plating is applied, and resistancebrazing is performed to the conductor terminal by a resistance welder. Abrazing material 8 is a solder of copper phosphide, composed by weightof P 5%, Ag 15% and Cu the remainder. The brazing material has athickness of 0.13 mm.

The resistance brazing condition is as follows: First stage heating:applied pressure 45 kg, current 6.2 kA, 1 sec Second stage heating:applied pressure 45 kg, current 6.8 kA, 1.5 sec

As a result, the molded multi-core conductive wire end portion and theconductor terminal are successfully joined with each other by copperphosphide solder.

FIG. 9B shows an example of connection by a rivet 10 using a fitting 9.The fitting 9 protects a terminal 5 and serves as a connection plate toother terminal platge 7. A hole 6 of the fitting 9 and a hole of theterminal are tightened by the rivet 10 to be fixed. As the material forthe rivet 10, Cu, Cu alloy, Al alloy, Fe series or the like can beapplied. If the connection is performed in this system, all processingsfrom the molded end portion to the end portion connection are performedin cold treatment, the multi-core conductive wire of the molded endportion structure being excellent in flexibility can be obtained withoutthermal damage.

Embodiment 4

A multi-core conductive wire is constituted in that a bundle of Cu-wireis formed by 2,413 wires each having a diameter of 0.05 mm, and sixbundles of wires constituted by 14,478 wires are arranged in three rowsand two stages in an arbitrary length (70 mm in this case) and then aremolded by cold compression.

The manufacturing processes of cold pressure-molding of this embodimentare similar to those of the first embodiment. In this embodiment,however, a mandrel is used so as to provide a desired hole diameterduring the temporary molding. The molded article has a shape of 0.2mm×8.1 mm and about 4.5 mm in thickness and the hole diameter is 4.5 mm.In this time, the pressure of the press is about 3 tons.

Thus the end portion of the multi-core conductive wires is molded in aprescribed shape and integrated by cold processing. FIG. 10 shows such amolded structure with a hole.

FIG. 11 shows an example where a molded end portion structure with ahole is connected to other conductor terminal. FIG. 11A shows astructure of screw connection. That is, a fitting 12 is used on themolded end portion and is tightened to a terminal plate 7 by a screw 11through a washer 13 so that the terminal plate 7 is connected to themolded terminal 5. FIG. 11B shows a structure of rivet connection. Thatis, a fitting 12 is used on the molded end portion, and a terminal plate7 and the molded terminal 5 are tightened by a rivet 14 so that theterminal plate 7 is connected to the molded terminal 5.

Embodiment 5

A multi-core conductive wire is constituted in that a bundle of Cu-wireis formed by 2,413 wires each having a diameter of 0.05 mm in anarbitrary length (70 mm in this case) and then molded by coldcompression..

The manufacturing processes of cold pressure-molding of this embodimentare similar to those of the first embodiment. The molded article has ashape of 6 mm×2.1 mm and about 2.3 mm in thickness (in FIG. 12A), andhas 6 mm in length and a wire diameter of about 2 mm (in FIG. 12B). Inthis time, the pressure of the press is about 0.8 tons.

The end portion of the multi-core conductive wire manufactured in suchmanner is connected to other conductor terminals as shown in FIGS. 12Aand 12B. FIG. 12A shows a connection example for a molded square shapeportion. That is, an end portion 5 subjected to molding in coldprocessing is inserted into an exclusive connection terminal 15manufactured previously and the terminal 5 is tightened by a screw 16 ofthe connection terminal 15 to be integrated. FIG. 12B shows a connectionexample for a molded round shape portion. That is, an end portion 5subjected to molding in cold processing is inserted into an exclusiveconnection terminal 17 manufactured previously, and the terminal portion5 is tightened by a screw 18 of the connection terminal 17 to beintegrated.

In the molded end portion structure by the cold pressure-molding of themulti-core conductive wire in this embodiment, since the strands areentangled with each other in disorder and the terminal portion is moldedin the irregular and uneven state, the high fixing force is exhibited.

Comparison Example

A multi-core conductive wire is constituted in that a bundle ofCu-stranded wire is formed by 2,413 wires each having a diameter of 0.05mm, and six bundles of stranded wires constituted by 14,478 wires arearranged in three rows and two stages in arbitrary length (70 mm in thiscase) and then molded by cold compression.

These multi-core conductive stranded wires are subjected to coldpressure-molding using a die used in the first embodiment. That is, themulti-core conductive stranded wires are arranged in the die and moldedinto a prescribed shape by applying a pressure using a press. The moldedarticle has a shape of 8.2 mm×8.1 mm and about 3.2 mm in thickness. Inthis time, the pressure of the press is about 3 tons.

The fixing force of the molded articles subjected to molding in theembodiments and the comparison example as above described was tested bythe peeling-off test. The peeling-off test in the case of the sixbundles were divided into the three bundles at the upper stage and thethree bundles at the lower stage, and the upper bundles and the lowerbundles respectively were grasped by a chuck and pulled by a tensiontester. Also in the case of the straight wires, the peeling-off test wasperformed in that the straight wires were substantially halved, and therespective wires were grasped by a chuck and pulled by a tension tester.Further in the case of a brazed molded article, the peeling-off test wasperformed in similar manner.

As a result, in the molded articles in the present invention, that inthe first embodiment exhibited a fixing force of about 4.5 kg, and thatin the second embodiment exhibited a fixing force of about 5.2 kg. Alsothe molded article in the third embodiment subjected to the brazingexhibited a fixing force of about 4.5 kg.

In the case of the molded article in the comparison example, when themolded article was mounted to the chuck of the tension tester, itcollapsed and the strength was zero.

Thus in any molded article manufactured in the present invention, it isclear that the fixing force of the molded portion is high. Also when themolded article is brazed, it is clear that higher fixing force isexhibited.

Also the connection in screw or rivet system has characteristics beingelectrically stable.

In the molded end portion structure manufactured in such manner, it isclear that the fixing force of the molded end structure itself is high.The satisfactory form can be obtained also in the connection to otherconductor terminals. That is, the molded end structure with less thermaldamage can be obtained and the multi-core conductive wire in highreliability becomes possible.

Embodiment 6

This embodiment as shown in FIG. 13 is constituted conductive wires 1being six bundles of stranded wires are obtained as in the firstembodiment, and a foil 36 of copper phosphide solder described in thethird embodiment is mounted on a terminal 5 of the multi-core conductivewires 1 so that it is brazed to other conductor, is previously molded asa clad on a surface of a copper conductor 38 and the member constitutedin this manner is also mounted on a terminal and molded integrally.

FIG. 14 is a sectional view of an electric resistance heater where thecopper conductor 38 with the solder foil 37 cladded thereon is joined bybrazing with the terminal 5 of the multi-core stranded wires 1. Thesolder foil 37 is held on and contacted with the terminal 5 between anupper electrode and a lower electrode, and pressure is applied and analternating current is flowed thereto. As a result, the local heatingand melting are produced between the terminal 5 and the solder foil 37and thereby the terminal 5 and the solder foil 37 are joined with eachother.

FIG. 15 is a perspective view showing a state where the upper conductor38 with the solder foil 37 cladded thereon is brazed on the terminal 5of the multi-core conductive wires 1. Such copper conductor 38 is joinedby the solder foil 37 and thereby the solder material is penetrated intothe terminal 5 and the terminal with high intensity can be obtained. Asshown in FIG. 10, the hole 6 is provided, and the connection to otherconductor by the screwing can be performed with high reliability.

Industrial Applicability

According to the present invention, the molded end portion structure ofthe multi-core conductive wire by the cold pressure-molding is molded inirregular and uneven state where the strands are entangled with eachother in disorder. Thus the multi-core conductive wire with high fixingforce can be obtained.

Also when the compressed end molded article is connected to otherconductor terminals, for example, in the connection by brazing, thesolder material wets the terminals and the molded article and herebygood joining can be achieved. Also in the connection by screw or rivetsystem, electrically stable characteristics can be maintained.

That is, the molded end structure with less thermal damage can beobtained because it is manufactured in the cold pressure-molding. Alsothe multi-core conductive wire with high reliability is confirmedbecause the connection portions are connected by the solder material orthe like.

What is claimed is:
 1. A multi-core conductive wire, comprising aterminal molded at an end portion of the multi-core conductive wire,said terminal being molded by subjecting to pressure-molding into astate where individual strands of the multi-core conductive wire areentangled with each other.
 2. A multi-core conductive wire, wherein themulti-core conductive wire is partially integrally molded by plasticworking, and individual strands of the multi-core conductive wire areentangled and coupled with each other at the partially integrally moldedportion.
 3. A multi-core conductive wire, wherein the multi-coreconductive wire is partially molded by subjecting to pressure-molding,and individual strands, located at the partially pressure-moldedportion, of the multi-core conductive wire are entangled and coupledwith each other.
 4. A multi-core conductive wire, wherein the multi-coreconductive wire constituted by a plurality of bundles is partiallyintegrally molded by subjecting to plastic working, and therebyindividual strands of the multi-core conductive wire are coupledintegrally with each other.
 5. A multi-core conductive wire, wherein anend portion of the multi-core conductive wire constituted by a pluralityof bundles is integrally molded by subjecting to pressure-molding, saidend portion comprising a terminal molded in such a manner thatindividual strands of the multi-core conductive wire are entangled andcoupled integrally with each other.
 6. A multi-core conductive wire asset forth in any one of claims 1 to 5, wherein the portion of themulti-core conductive wire molded by subjecting to pressure-molding orplastic working is connected to other conductor by brazing or mechanicalmeans.
 7. A method of manufacturing a multi-core conductive wire,comprising the steps of: processing the multi-core conductive wire intoa state where individual strands of the multi-core conductive wire arepartially entangled with each other; temporarily molding the processedportion of the multi-core conductive wire; and further applying pressureto the temporarily molded portion for pressure-molding or plasticworking.
 8. A method of manufacturing a multi-core conductive wire,comprising the steps of: processing an end portion of the multi-coreconductive wire into a state where individual strands of the multi-coreconductive wire are entangled with each other; and processing theprocessed end portion by subjecting to pressure-molding or plasticworking; wherein the individual strands are coupled with each other sothat they are not separated.
 9. A method of manufacturing a multi-coreconductive wire, comprising the steps of: processing an end portion ofthe multi-core conductive wire constituted by a plurality of bundlesinto a state where individual strands of the multi-core conductive wireare entangled with each other; and processing the processed end portionby subjecting to pressure-molding or plastic working, wherein theindividual strands are entangled and coupled with each other.
 10. Amethod of manufacturing a multi-core conductive wire as set forth in anyone of claims 7 to 9, wherein said multi-core conductive wire comprisesstranded wires.